1. Field of the Invention
The present invention relates to surface mount resistors. More particularly, it relates to current sense resistors using a metal element. Still more particularly, though not exclusively, the present invention relates to surface mount resistors having an increased mechanical strength.
2. Problems in the Art
Surface mount resistors have been produced in the electronics industry. Their construction has typically been comprised of a flat rectangular resistive metal strip with high conductivity metal terminals welded to the ends of the resistive metal strip to form the electrical termination points. The resistive metal strip may be "adjusted" to a desired resistance value by abrading or by using a laser to remove some of the resistive material. A protective coating, for example epoxy, is then applied over the resistive material to provide protection from various environments to which the resistor may be exposed as well as providing strength to the resistor.
Typical prior art resistors are adjusted to a desired resistance by making lateral plunge cuts from the sides of the resistor material making a serpentine-type pattern. While these plunge cuts result in a resistor with a desired resistance, the lateral cuts across the face of the resistor degrade the mechanical strength of the device, in particular, the beam strength of the device. In some applications, it is desirable to put a physical load on the resistor across the face of the resistive metal. With the prior art employing lateral plunge cuts across the resistive metal, substantially all of the structural strength comes from the epoxy coating rather than the resistive metal. Therefore, it can be seen that there is a need for an improved surface mount resistor having an increased beam strength while still allowing the resistance of the resistor to be adjusted.